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FC_plate_tilted

 

 

The procedure FC_plate_tilted(Fluid$, T_s, T_infinity, P, L, W, tilt : h, Nusselt, Ra) returns the heat transfer coefficient and Nusselt number for a tilted flat plate (heated or cooled) of horizontal width W and height L that is tilted with respect at angle tilt with repsect to horizontal.  The width of the plate is assumed sufficiently large such that end effects may be neglected. The units of the inputs and outputs depend on the unit settings in EES.  The magnitude of gravity is assumed to be 9.807 [m/s^2] in SI units. 

 

Inputs:

Fluid$ - string name of any fluid in the EES database. The fluid can be an ideal gas or a real fluid

T_s - surface temperature of the plate in [C], [K], [F], or [R].

T_infinity - bulk temperature of the fluid in [C], [K], [F], or [R].

P -  ambient pressure in [Pa], [kPa], [bar], [MPa], [atm], or [psia]

L - height of the plate [m] or [ft] (if it were oriented vertically)

W - width of the plate [m] or [ft] in the horizontal direction

tilt - angle of the plate with respect to horizontal (degrees or radians)

 

Outputs:

h -  heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R] 

Nusselt - Nusselt number [-]

Ra - Rayleigh number [-]

 

Notes:

This function implements the method of Raithby and Hollands (1998) that uses the horizontal and vertical plate correlations to estimate the heat transfer from a heated plate inclined at an arbitrary angle, 0° < z < 180° as described in section 6.2.2 of Nellis and Klein.  

 

The function is specifically coded for a heated plate (i.e., T_s>T_infinity).  However, if T_s<T_infinity, the function internally changes the tilt to be 180-tilt.  The net result is that the heat transfer coefficient for a cooled plate facing up is the same as for a heated plate facing down.

 

Example:

$UnitSystem SI deg K J Pa

$VarInfo h units=W/m^2-K

Fluid$='air'

T_s=350 [K]

T_infinity=300 [K]

P=101300 [Pa]

L=0.5 [m]

W=0.5 [m]

tilt=45 [deg]

Call fc_plate_tilted(Fluid$, T_s, T_infinity, P, L, W, tilt: h, Nusselt, Ra) 

 

{Solution: 

h=5.245 [W/m^2-K]

Nusselt=23.85

Ra=4.561E+06 

}

 

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